I have 3 positive pregnancy test but not pregnant through tvs why? Pls enlighten me!now im bleeding

usually, @ 5weeks may nadedetect na sa transvag ultrasound. baka maaga pa? if bleeding ka, i suggest pacheck ka uli sa doc mo. baka kasi maaga pa kaya wala madetect sa ultrasound. im not sure if implantation bleeding yan or miscarriage. better if si doc mo magsabi sayo on what to do.